What does extrasystole mean?
An extrasystole is a premature contraction of the heart — a beat that arrives earlier than the normal rhythm dictates, originating from an ectopic focus in the atria or ventricles rather than the heart's natural pacemaker. Often described by patients as a 'skipped beat' or flutter, it is actually an extra beat followed by a brief compensatory pause. Extrasystoles are extremely common: most people experience them at some point, often without noticing, and in healthy hearts they are usually benign. They may be triggered by caffeine, stress, fatigue, or alcohol, though frequent or complex extrasystoles can warrant medical evaluation. The word belongs primarily to clinical vocabulary — cardiologists speak of atrial or ventricular extrasystoles on ECG findings — but it appears in patient-facing health writing too. Its adjective form is 'extrasystolic', and its relatives 'systole' and 'diastole' describe the ordinary phases of the cardiac cycle.
nounA contraction of the heart that occurs earlier than expected, interrupting the normal rhythm; a premature heartbeat arising from an ectopic focus outside the usual pacemaker.
- An isolated premature contraction of the heart, arising from the atria or ventricles, that disrupts the normal cardiac rhythm.
"The cardiologist reassured her that the occasional extrasystole she felt was harmless."
"Holter monitoring revealed frequent ventricular extrasystoles during periods of stress."
"Most people experience an occasional extrasystole without ever being aware of it."
Regular plural; commonly used in clinical contexts such as 'frequent extrasystoles'.
"Ambulatory monitoring recorded numerous extrasystoles over the twenty-four-hour period."
That sudden 'skipped beat' you sometimes feel isn't your heart stopping — it's an extrasystole, an extra squeeze sneaking in ahead of schedule.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of extrasystole
Extrasystole derives from the Greek 'systolē', meaning 'contraction' (from 'systellein', to draw together), combined with the Latin-derived prefix 'extra-', indicating something additional or beyond the norm. The term was coined in nineteenth-century European medical literature as physicians began describing premature beats observed at the pulse and, later, on early electrocardiograms. It shares its Greek root with 'systole', 'diastole', and 'asystole', all terms for phases or states of cardiac contraction.
Related word forms
How extrasystole is actually used
A clinical and technical term used mainly in cardiology and medicine; in everyday speech, people are more likely to say 'skipped beat' or 'palpitation'. The adjective form is 'extrasystolic'.
Easily confused with extrasystole
Systole is the normal phase of heart contraction that pumps blood out, while an extrasystole is an extra, premature contraction occurring outside the regular rhythm.